多体素1H-MRS和DWI对脑肿瘤强化周边区的评价

Evaluation on perienhancement area of brain tumors with multivoxel 1H-MRS and diffusion weighted imaging

目的探讨多体素1H-MRS及DWI在脑肿瘤强化周边区中的价值。方法脑肿瘤患者35例,DWI测量肿瘤不同部位信号值,计算ADC值;多体素1H-MRS采集NAA、Cho、Cr等波峰,计算脑肿瘤不同区域、不同脑肿瘤近侧瘤周区及高、低级星形细胞瘤的多种代谢物比值平均值。结果DWI示肿瘤强化区,脑膜瘤与星形细胞瘤、转移瘤间及高、低级星形细胞瘤间有显著性差异(P<0.05);近侧瘤周区,星形细胞瘤与另两者间有统计学差异(P<0.05);远侧瘤周区,三者比较无统计学意义(P>0.05)。多体素1H-MRS示肿瘤强化区NAA/Cho、NAA/Cr和Cho/Cr平均值与参照区比较有显著性差异(P<0.05);近侧瘤周区,不同肿瘤间及高、低级星形细胞瘤间,多组代谢物比值具统计学差异(P<0.05)。结论多体素1H-MRS、DWI与MRI增强检查相结合有助于脑肿瘤的鉴别诊断、确定病灶浸润范围、星形细胞瘤的分级诊断等。

Objective To investigate the value of multivoxel proton magnetic resonance spectroscopy （1 H-MRS） and diffusion weighted imaging （DWI） in perienhancement area of brain tumors. Methods Thirty-five intracranial tumor patients were recruited in this study. The ADC values were calculated within various areas and the difference of the mean ADCs were made by analysis of variance; Spectra of different areas were taken and fitted areas in the spectrum for NAA, Cho, Cr and other metabolite peaks were measured and NAA/Cho, NAA/Cr, Cho/Cho （normal）, Cho/nCr, Cho/Cr ratios were calculated for each voxel. Results The mean ADCs from enhanced areas of brain tumors were significantly different between meningiomas and astrocytoma or metastases, high and low grade astrocytoma. The ADC values of perienhancement for astrocytoma, metastases and meningiomas were statistically significant different. There was no significant difference among distal areas. In multivoxel ^1H-MRS from enhanced areas of the lesion, the ratios of NAA/Cho, NAA/Cr and Cho/Cr changed significantly when compared with that of normal brain tissues （P〈0.05）, but there was no significant difference between astrocytoma and metastases （P〉0.05）. In voxel from perienhancement region, the mean values of different metabolite peak ratios revealed strong correlations between metabolite concentrations and tumor types, high and low grade astrocytomas. Conclusion Multivoxel ^1H-MRS, DWI and enhanced MRI will be useful in the diagnosis and differential diagnosis of tumors, defining the border of tumors and making the histological classification of astrocytoma.